Thank you for your further explanation. I just want to use this data in other packages. I think that ASCII file is likely better. Because I don't know the format of the binary file? how to find it?
In addition, do you have any better methods to save the sparsity structure picture of the matrix? Now, I use "-mat_view_draw" to do this. However, the speed is very slow and the picture is small. I want to get a big picture and directly save it to the disk? could you give me some advice? thanks a lot. Regards, Yujie On 1/23/08, Matthew Knepley <knepley at gmail.com> wrote: > > On Jan 22, 2008 11:01 PM, Yujie <recrusader at gmail.com> wrote: > > Dear Matt: > > > > thank you for your reply. Do you have any method to generate an ascii > file > > of the huge sparse matrix? thanks > > I think you miss my point. The PETSc function is not a bad way to generate > ASCII matrices. ASCII matrices make "no sense" for large operators. > > Matt > > > Regards, > > Yujie > > > > > > > > On 1/23/08, Matthew Knepley <knepley at gmail.com> wrote: > > > On Jan 22, 2008 8:50 PM, Yujie <recrusader at gmail.com> wrote: > > > > Hi everyone: > > > > > > > > #include "petsc.h" > > > > PetscErrorCode PetscViewerASCIIOpen(MPI_Comm comm,const char > > > > name[],PetscViewer *lab) > > > > > > > > #include "petsc.h" > > > > PetscErrorCode PetscViewerBinaryOpen(MPI_Comm comm,const char > > > > name[],PetscFileMode type,PetscViewer *binv) > > > > > > > > if the difference between them is that one for ASCII output and the > > other > > > > for Binary output, why are there different parameters? > > > > > > It is historical. If you want to be generic, you should use > > > > > > PetscViewerCreate() > > > PetscViewerSetType() > > > PetscViewerFileSetMode() > > > PetscViewerFileSetName() > > > > > > which can create both. > > > > > > > The speed to output matrix is very fast when I use > > PetscViewerBinaryOpen. > > > > However, when I use PetscViewerASCIIOpen, I can't get the matrix > output. > > the > > > > code always is running and it has taken about one day! what's the > > problem? > > > > thank you. > > > > > > ASCII files do not make sense for large matrices. You should use > binary > > files. > > > > > > Matt > > > > > > > Regards, > > > > Yujie > > > > > > > > > > > > > > > > > > > > > > > > -- > > > What most experimenters take for granted before they begin their > > > experiments is infinitely more interesting than any results to which > > > their experiments lead. > > > -- Norbert Wiener > > > > > > > > > > > > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which > their experiments lead. > -- Norbert Wiener > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20080123/f68a27c7/attachment.htm>
